“The agency made this decision as a result of the data gathering process and new evidence collected at the site today,” the FAA said in a statement. “The ground will remain in effect pending further investigation, including examination of aircraft’s flight data recorders and cockpit voice recorders.”

Grounding the 737 MAX reportedly came at the direction of Boeing itself, despite the company asserting its certainty in the plane’s safety.

“Boeing has determined — out of an abundance of caution and in order to reassure the flying public of the aircraft’s safety — to recommend to the FAA the temporary suspension of operations of the entire global fleet of 371 737 MAX aircraft,” Boeing said in a statement of its own.

The company also noted that it “continues to have full confidence in the safety of the 737 MAX.”

Boeing will be permitted to finish manufacturing any 737 MAX currently in production, but will not be allowed to use them.

Sea-Tac Airport sees the 737 MAX roughly three times across the 1,200 to 1,300 flights that fly through daily.

This comes after the second fatal crash of a 737 MAX inside of five months, and after Canada, Europe, and others had already opted to ground the plane. The FAA had originally balked at doing the same on Tuesday.

A total of 189 people died in a Lion Air crash out of Indonesia on Oct. 29, 2018, when the plane nose-dived into the ocean. A total of 157 people died in the Ethiopian tragedy Sunday. Similar to the Indonesian crash, the pilot of the plane in Ethiopia sent a distress call shortly after takeoff.

Boeing has over 300 737 MAX planes in service across the globe. An estimate from a pair of Wall Street firms says that grounding the entire inventory for just three months would cost the company anywhere between $1 billion and $5 billion.

Meanwhile, a Seattle firm has already filed a wrongful death lawsuit against Boeing on behalf of the families of 17 victims of the fatal Lion Air crash. The suit alleges that Boeing concealed a key system in the 737 MAX that caused the October crash, all in the name of boosting sales.

“That mistake is driven by market forces trying to make the plane more competitive against Airbus, at a lower price, at least as far as training,” said Charles Herrmann, the principle attorney with the firm leading the lawsuit.